Mechanical stoker.



PATENTED FEB. 13, 1906.

y J. A. CALDWELL. MECHANICAL STCKLL.

APPLIUATION IILED FEB.15,1905.

4 SHLLTSQCHBET 1.

Af. ML/aww.

PATBNTBD PEB. 13, 1906.

4 SHEETS-SEBI@ 2.v

J. A. CALDWELL. MECHANIGAL STOKER. APPLIGATION FILED rnn.15.1`9o5.

4 SHEETS-SHEET 4.

PATENTED FEB-13, 19GB.

LPM CALDWELL. MECHANICAL STUKER.

APPLICATION FILED FBB.15,1005` WVM/moge@ heating effect obtainable from different kinds' of coa F' alii.

UNITED srArEs PATENT orrron.

Joan a.' riALnwELL, or MoNfroL/na. New JERSEY. 'wiser-murrine. aroma.

a citizen of the United States, residing at Montclair, in the county of Essex and State of New Jersey, have invented certain vnew and luseful Improvements in iriechanical Smokers,-

of which the tollowing 1s a specification.

My invention relates to mechanical stokers for automatically supplying fuel to furnaces in general and to steam-boiler furnaces in particular. v

The objects of my invention are to provide 4suitable mechanical means for regulating andl for varying the distribution of coal upon a grate, so as to secure the'best and quickest also, toprovide certain improved detail constructions in connection with my improved stoker, so as to insureits proper and efficient operation at all times.

the means hereinafter specified, and set forth more particularly in the claims.

In the accompanying drawings, Figure 1'is a side view looking toward the left in Fig.' 2 of aboiler-furnace equipped with my improved appliances, the furnace itself being shown in section, the means for supplying coal to the shovel, however, not being shown therein, Fig. 2 being a front view of a portion of a boiler-furnace provided with my improved mechanical stokers. Figs. 3 and 4 are detail views illustrating portions of the stoker mechanism, Fig. 3 being a section along line 3 3 in Fig. 2 and Fig. 4 an end view of the construction shown in Fig. 3.

5 is a diagrammatic illustration of a de- Fig. 6 is a section along line 6 6 in Fig. 4 looking toward the left and illustrating more particularly the shovel and the box in which it'travels, while Fig. 7 is a sectionalong line 7 7 in Fig. 6 looking toward the' right. Fig. 8 is a side view, partly `in section,

4of a bracket with antifriction-rollers upon which the shovel-shaft is mounted, while Fig. 9 is a section along line 9 9 in Fig.A 8. Fig. 10 is a front view, and` Fig. 11 ay side .view, of the gearing and` connecting'- parts employed by rre for actuating the shovel# shaft. Fig. l2 is a side view, and FigA 3 a p front View, and Fig. 14 a top z iew, ofthe upper portion of the mechanism employed for imparting movement from the shaft operating the stokers to the rocking grate employed by me. Fig 15 illustrates a modificationv of a camwheel forming porti n of my Specification of Letters Patent.- A-pp'iraaon ned rams, 15,1905. serai iro. 245,667.

l accomplish these and other useful objects bv tween the hub ofthe shovel and shaft Patented Eeb. ie, ieee.

apparatus. Fig. 16 is a detail, partly cross-section and partly in end view, and Fig. 17 partly a longitudinal section and partly a front view, of the same detail. -Fig. 18 is an elevation, partly' in section, of mech-- anism for supplying coal to thev shovel.

lorresponding characters of .reference throughout the different views refer to cerresponding parts. i l

In said drawin s,'10 is the front portion of a boiler supporte upon brickwork 11. v 12 is the metallic boiler front 5A 13, the 'bridge-wall, 14, the furnace; 15, the furnacegrate, and 16 the ash-pitunderneath the same 17 ,is an opening extending through parts 11 and 12, Ithrough which coal or other fuel is proJected by the stoker upon the grate from the outside ofthe furnace. 18 represents the openings to the ash-pit. 19 is themain shaft for operating a number of mechanical stokers forv supplying either one for a multiplicity of furnaces with coal or other fuel. y

20 20` are hoppers attached to the boilerfront and from which'coal or other similar lfuel is supplied to the stokers, one hopper enerall su l n one Stoker. g *21" 21,3are hiiacllrefs attached to the hoppers and carryin the bearings for main shaft 19.

Each of t e stokers comprises a shovel for throwing coal upon the lire and aram for supplying a predetermined quantity of fuel to the shovel and mechanisms actuated by shaft 19, which revolves in the direction of the arrow in Fi 3 for operating said parts.

22 is a shove which oscillates with a shaft 23 ets are secured to the boiler-front.

25 25 are roller bearings interposed be- 26 is a ram ywhich is adapted to slide toward and away from the boiler-front upon the bottom'27 of the hopper'. nearest to thefurnace-front lreached by the ram is illustrated in Figs. 3 and 18. Prior to the ram moving into said position coal mov ing downward between walls 28 28 of the hopper will be` deposited between. said ram mounted upon brackets 211, which brach-- The position and point A, and as the ram moves toward i,

`point A. in the direction of the arrows 'will be precipitated through an opening 29 m. the

bottom of the hopper upon a deflector 3G,

either rigidly or adjustably attached to the;

boiler.- front and extending forward and downward. therefrom and will from there ydrop `upon a concave platform lwhilethe wardwill shovel 22, as woll as arm La, be swung and the greater will' be the tension on said spring, and consequently when the said ram-tappets 34, 34', and 34X pass from contact with shovel-tappet 4l and spring 49 ish thereby permitted to assume its nornial position, and to thus be relieved of tension, the greater a force will be applied to the shovel as -.it projects .the fuel into the furnace and the tion of .my preferred form of cams 36, 36

and 36X and will now describe how the different tappets 34, 34', and 34X are affected by it.

Assuming gear-wheel to have thirty teeth and gear-wheel v35 tohave thirty-one teeth and pinions 37 and 33 to have ten teeth each, then upon each complete revolution of gearwheel 33 gear-wheel 35 will fall behind to the extent ofone-t-hirtieth of the periphery of gearwheel 33,v corresponding-with a -falling behind amounting to one-tenth of the length.

ofcam" 36, or if the original position of amtappet 34 was-aba on cam 36, while also engagement with shovel-tappet 41, after a complete revolution of gear-wheel 33 it will ybe at b on said cam, the distances between points a b &c., being each one--tlrtieth of theenti-re circumference. The construction of my cams is such that points a, a', and aX are equidistant from shaft 19, while points i),

b, and-bX are also equidistant therefrom, but. farther away fro-m the shaft than points a, a',

and ax, this arrangement being continued with reference to points, asc, c', and cx, &c. The relative .positions of cams 36, 36', and 36X are such' that, providing.,r at the beginning cam-tappeti34 contacts with cani 36 at a, while also in operative contact with shoveltappet 41, after one-third of a revolution of gear 33 cam-tappet 3 4', While coacting with shovel-tappet 41, will contact with point o', after another one-third of a revolution camtappet 34X will so contact withcx, and three equal throws of coal will thus .have been delivered directly adjoining the furnace-front.

While gear 33 is making'its next revolution;

cam-tappet 34 will coact with oint b, 34 with b', and 34 with bx, while a so coacting with shovl-tappet 41', until another and. adjoin'ingvone-tenth of the depth of the furnace has been covered with three charges of coal, and this mode of operation .is continued. until cam-tappet 34X contacts with jx, whenl the entire depth of the furnace will have been covered with a'layer of coal of approximately even thickness, after which cam-tappet 34 will again simultaneously contact with point u and shovel-tappet 41, whereby the deposition ofa new layer of coal will be started near thev boiler-front.

Where I employ cam'sfas 36, all of equal length, as illustrated in llig: 15, having a continuous grad ual curvature, I obtain a result approximately equal to that ust described, each successive throw, however, being shifted to the extent of about onc-thirtieth of the depth of the furnace away from the boiler-front as compared with the precedingr one. v

The above modes of supplying fuel to the furnace are particularlysuited for anthracite coal. When it is desired to apply bitumi- .nou's coal in thin layers, l substitute for pinion 38, having ten teeth, another pinion havvingnine teeth to coact with gear 35 of thirtyone teeth. This will upon each com plete rdvolution' of gear 33 make gear 35 fall back four teeth and not one, as described above. starting with cam-tappet 34 in contact with a. and with shovel.- tappet 4]. cam tappet 34 will next contact with I1', 34 with cx, 34 with d, &c;, thus making each throw difl'erL ent from the preceding one and Vcovering the whole depth of the furnace by only ten throws and making the layer so supplied only onethird as thick as thatsupplied in the case of anthracite. Of course the number and the Thus' l extent of throws desired. can be regulated by the use of gearings proportioned accordingly.

It is desirable to assist the uniform distribution of the fuel as the same is being deposited upon the grate by the shovel and to equalize the same as farras practicable and particularly ina lateral direction, and for that purpose I prefer the grate-bars 59 to be placedupon'l frames 60, extending in the direction inl which the throw of coal takes place f and to arrange for rocking the same laterally to such direction simultaneously with the operation of the Stoker, land to accomplish this I provide a bevel-wheel 61 on shaft 19, which Wheel meshes with another bevel-Wheel' 62 on a-shaft 63 and carries a stud 65, adjustable in a slot 66 along a crank 64 toward and away from shaft 63; Said stud actuates a slotted lever 67, fixedly secured to one end of shaft 68,V which shaft oscillates Within a bearing 69, secured to the boiler-front, and carries at itslrear end a lever 70, provided with a pivot 71, engaging with a notch on the under side of a bar 7 Z, 'inning parallel with the boiler-front and having a, series of perforations into which lit pivots 73 on levers 74 ori-- one Stoker, plain disks instead of gear-wheels With-tappets 34 34', and 34X, however, being IIO tial means embo lyin provided in each case. For shaft 39 one continuous shaft Would then have to be substituted7 on which the diHerent 'pinions 38, meshing -With gears 35, Would have to be mounted.

The employment of antifriction-rollers between shaft 23. and its bearings and between eyell and pin`47 is of particular importance in this case not only on account ofthe sudden intense and reciprocating .strainsproduced at these points, but also because on account of the close ypror'ii'mity to the furnace lubrieating-oil cannot be suitably employed there.

'1. 'ln ,a mechanical Stoker, the combination with@ shovel, of a cam, .a cani-tappet adapted to engage'with said cam, mechanisminter-- posed between said camtappet land the: shovel for actuating saidshovel, and differential means for producing-movement ,ofsaid carnl-tappet with reference` to the cam'. l

2. In a mechanicalstoker, the combination with a shoveLof `a cam, a cam-tappet, adapted to "engage with said cam,-mechanism interposed. bei-,Ween said cam-,ta pet and the shovel foractuat'- .saidshove ,and differena detachable Agear- Wheel for rocluc'A re tive movements y'be'- tween sa' cama'ni said tappet. l y

.3.' ln a mechanicalstoker, gthecombina tion with a shovel, of a shaft, .a getij-Wheel1110111111-,y ed-'on :said shaft; a cam-tappet :adjusted to'. re'- volve gear-Whed, a second .gear.

-. yw-leel mounted on said sha-ft, a 'cam-adjusted '3S Atoreyo'lve with said second-.- ear-wheel means. interposed between said' gear-jv which said 'tappet and saidshovel are mounted, and means for actuatin" said cam for 1m parting movement to said s ovel-tappet, said tappet beinggconstructed in sections adjust- L ablein-their relative positions. 'j

\ y 5. In a mechanical Stoker, thecombination lwith a shovel, of mechanism comprising a '.cam, a shaft; and a shovel-tappet 'mounted 'upon said shaft and'adapt'ed to receive movesaid ltapprt beingv constructed in sectionsrprcH vided W'ith serrated surfaces"engagingiwith 'each other, and means'iforyaiying ther-sia tive pbs'i-tions vof .said serrated surfaces.

-' 6. The c'zombination-.1M-ith@J furnace, -0f an oscillating shovel', meansl v'for actua-ting said shovel, the free edge of theshovel'being-pro-` videdfwith teeth extending at ldiffer-ent an- -gles with respect to the face of the shovel.

. In testimony whereof-1 have signed my name -to this specification, inthe presence of -tWo subscribing Witnesses'. this 105th Vday of Elwanessesi I l i HORCK" 55 ment from such c am for actuatingfsaid shovel 

